1. Technical Field
The present invention relates to a recording medium determining device and a recording medium determination method that determine, for example, the type of recording medium such as paper, on which an image is recorded.
2. Related Art
In technologies that record an image on a recording medium such as paper or a resin sheet, there are cases where it is necessary to determine the type of recording medium used in order to optimize the recording conditions or a transport form according to, for example, the characteristics of the recording medium. There are technologies able to be used to this end which use the optical characteristics of the recording medium such as disclosed in JP-A-08-314327 and JP-A-2005-315856.
In the technology of the disclosure in JP-A-08-314327, the type of recording medium is determined on the basis of the intensity ratio of the regular reflection light and diffused reflection light received by a light receiving element along with light from an LED that is a light emitting element being made incident with respect to a recording medium. In the technology of the disclosure in JP-A-2005-315856, the type of recording medium is determined on the basis of each light amount of regular reflection light and diffused reflection light when the medium is irradiated with infrared light, and the light amount of a fluorescent component emitted from the recording medium when the medium is irradiated with ultraviolet light.
As types of recording media, there are numerous types in circulation in the market. Therefore, there is demand for accurately determining the type thereof; however, the technologies of the related art are unable to respond to such demand. For example, in the technology of the disclosure in JP-A-08-314327, because the determination is simply performed only with the intensity ratio of the regular reflection light and the diffused reflection light, a plurality of recording media with similar characteristics on this point are unable to be determined. In addition, in the technology of the disclosure in JP-A-2005-315856, although the reflection characteristics with respect to infrared light and the fluorescence characteristics with respect to ultraviolet light are taken as a determination reference, according to the findings described later of the inventors of the present application, the difference between the reflection characteristics of various recording media with respect to infrared light is extremely small, furthermore, the fluorescence with respect to ultraviolet light is mainly due to a brightening agent, and determination of the type of recording medium not including a brightening agent is unable to be made.